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nodejs/test/parallel/test-child-process-double-pipe.js
Vse Mozhet Byt 8b76c3e60c test: reduce string concatenations
PR-URL: https://github.com/nodejs/node/pull/12735
Refs: https://github.com/nodejs/node/pull/12455
Reviewed-By: Refael Ackermann <refack@gmail.com>
Reviewed-By: Gibson Fahnestock <gibfahn@gmail.com>
2017-05-05 17:39:05 +03:00

117 lines
3.2 KiB
JavaScript

// Copyright Joyent, Inc. and other Node contributors.
//
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// copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
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// following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
// USE OR OTHER DEALINGS IN THE SOFTWARE.
'use strict';
const common = require('../common');
const assert = require('assert');
const os = require('os');
const util = require('util');
const spawn = require('child_process').spawn;
// We're trying to reproduce:
// $ echo "hello\nnode\nand\nworld" | grep o | sed s/o/a/
let grep, sed, echo;
if (common.isWindows) {
grep = spawn('grep', ['--binary', 'o']),
sed = spawn('sed', ['--binary', 's/o/O/']),
echo = spawn('cmd.exe',
['/c', 'echo', 'hello&&', 'echo',
'node&&', 'echo', 'and&&', 'echo', 'world']);
} else {
grep = spawn('grep', ['o']),
sed = spawn('sed', ['s/o/O/']),
echo = spawn('echo', ['hello\nnode\nand\nworld\n']);
}
/*
* grep and sed hang if the spawn function leaks file descriptors to child
* processes.
* This happens when calling pipe(2) and then forgetting to set the
* FD_CLOEXEC flag on the resulting file descriptors.
*
* This test checks child processes exit, meaning they don't hang like
* explained above.
*/
// pipe echo | grep
echo.stdout.on('data', function(data) {
console.error(`grep stdin write ${data.length}`);
if (!grep.stdin.write(data)) {
echo.stdout.pause();
}
});
grep.stdin.on('drain', function(data) {
echo.stdout.resume();
});
// propagate end from echo to grep
echo.stdout.on('end', function(code) {
grep.stdin.end();
});
echo.on('exit', function() {
console.error('echo exit');
});
grep.on('exit', function() {
console.error('grep exit');
});
sed.on('exit', function() {
console.error('sed exit');
});
// pipe grep | sed
grep.stdout.on('data', function(data) {
console.error(`grep stdout ${data.length}`);
if (!sed.stdin.write(data)) {
grep.stdout.pause();
}
});
sed.stdin.on('drain', function(data) {
grep.stdout.resume();
});
// propagate end from grep to sed
grep.stdout.on('end', function(code) {
console.error('grep stdout end');
sed.stdin.end();
});
let result = '';
// print sed's output
sed.stdout.on('data', function(data) {
result += data.toString('utf8', 0, data.length);
util.print(data);
});
sed.stdout.on('end', function(code) {
assert.strictEqual(result, `hellO${os.EOL}nOde${os.EOL}wOrld${os.EOL}`);
});